Dynoed my 996 C4 today
#31
#32
Race Car
#33
Race Director
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I haven't done a dyno pull in...6 years? And never on a Porsche, so there are specifics (is the number coming from a bung-mounted O2 sensor or from the tail pipe sniffer), etc.
One piece of tuning advice: Watch a bunch of YouTube dyno disaster videos. Don't do those things.![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
OP, if you're happy with the power and your car isn't getting sooty, running a little rich isn't necessarily a bad thing....
One piece of tuning advice: Watch a bunch of YouTube dyno disaster videos. Don't do those things.
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
OP, if you're happy with the power and your car isn't getting sooty, running a little rich isn't necessarily a bad thing....
Last edited by 5CHN3LL; 05-25-2016 at 01:45 PM.
#34
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Tuning motors will be varied depending on type. For example, typical Honda inline motor likes to see as close to stoich as possible with a bit of safety margin, even if knock sensor is used. That's where they make some good power.
With the M96 boxer configuration however, it seems to be the best between 13-13.5:1 ratio. These are only from past observations as I personally only have experience tuning on other motors.
I'm sure someone like Jake can probably give a more definitive answer.
With the M96 boxer configuration however, it seems to be the best between 13-13.5:1 ratio. These are only from past observations as I personally only have experience tuning on other motors.
I'm sure someone like Jake can probably give a more definitive answer.
#35
Captain Obvious
Super User
Super User
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Considering how rich that graph shows and how hectic the Hp/Tq curves get when this happens makes me wonder what exactly this engine is making. The other thing to consider is that the tail pipe probe was only sampling one bank and even then, the sensor this far downstream and can become inaccurate. Would interesting to see if a stock tune and all stock parts put back would improve the A/F and the curves (not talking about actual power values).
#36
Race Director
#37
Three Wheelin'
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the A/F ratios look good - those results are with stock cats - a fully accurate AF ratio is gained only if you place the sensor 3" after the merge collector of the headers - but since the stock cats are being used... that is not possible... as a result the readings with sensor in the tailpipe show 1-1.5 richer than they really are !!! your car is making great power and "smoothing" doesn't appear to be a concern here IMHO. Curious to see the power bump you'll be making with 200 cell cats... I'm thinking you'll have 7-8 lb/ft more from 4500 and up.
when you getting the new cats installed?
when you getting the new cats installed?
#38
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the A/F ratios look good - those results are with stock cats - a fully accurate AF ratio is gained only if you place the sensor 3" after the merge collector of the headers - but since the stock cats are being used... that is not possible... as a result the readings with sensor in the tailpipe show 1-1.5 richer than they really are !!! your car is making great power and "smoothing" doesn't appear to be a concern here IMHO. Curious to see the power bump you'll be making with 200 cell cats... I'm thinking you'll have 7-8 lb/ft more from 4500 and up.
when you getting the new cats installed?
when you getting the new cats installed?
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I will make an appointment with my shop to get the dyno done again and post the results in the next few weeks.
#39
Former Vendor
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Make sure the software wasn't set for a flywheel HP correction factor. Mustang and some other dynes will allow the power figures to be corrected for expected drivetrain losses, not the net power at the wheels.
I never correct to flywheel power, if I want flywheel HP figures, I put the engine, on my engine dyno.
If those are net power figures with no flywheel HP correction, thats the strongest stock internal 3.6 on the planet. Congrats.
I never correct to flywheel power, if I want flywheel HP figures, I put the engine, on my engine dyno.
If those are net power figures with no flywheel HP correction, thats the strongest stock internal 3.6 on the planet. Congrats.
#40
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Jake, I just left a message with my shop to ask about the correction factor. I'm hoping it's not the case and my 996 is as strong as the numbers said. I'll update when I hear back from them.
#41
Former Vendor
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These are abnormally high based on the tens of thousands of graphs that I have. All Dino's read differently, and you might just have the strongest 3.6 on the planet.
#42
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We'll see when I get dynoed again with all this information. I'll keep you folks updated.
#43
Former Vendor
#45
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Make sure the software wasn't set for a flywheel HP correction factor. Mustang and some other dynes will allow the power figures to be corrected for expected drivetrain losses, not the net power at the wheels.
I never correct to flywheel power, if I want flywheel HP figures, I put the engine, on my engine dyno.
If those are net power figures with no flywheel HP correction, thats the strongest stock internal 3.6 on the planet. Congrats.
I never correct to flywheel power, if I want flywheel HP figures, I put the engine, on my engine dyno.
If those are net power figures with no flywheel HP correction, thats the strongest stock internal 3.6 on the planet. Congrats.
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